Timeliness and Quality of Care for Elderly Patients With Acute Myocardial Infarction Under Health Maintenance Organization vs Fee-for-Service Insurance

Abstract

AT THE TIME of this report, approximately 5 million Medicare patients received care from capitated health maintenance organizations (HMOs), representing a 360% increase from 1991; this number is expected to grow to more than 12 million by 2005.1 A common perception is that economic incentives in HMOs may reduce the speed and provision of urgent, essential care, especially in vulnerable patients like the elderly.2- 4 Unfortunately, there are virtually no data showing how the rapid shift to managed care may be affecting the quality of acute care for elderly patients.5,6

Some organizational processes and incentives in HMOs may raise the quality of care for acute conditions, while others may lower quality. For example, large HMOs often have 24-hour telephone triage systems and patient education to encourage patients with acute conditions to use emergency transportation to the hospital. Health maintenance organizations may also be more likely to establish quality-improvement systems (eg, treatment protocols or clinical pathways).7 Finally, HMOs are more likely to employ younger physicians, who may have more up-to-date knowledge about the safety and efficacy of newer drug treatments.8,9

On the other hand, in efforts to contain costs, primary care gatekeepers in HMOs attempt to reduce the inappropriate use of emergency departments, specialty care, and hospital care. Conceivably, this might result in delays in approval of the necessary use of ambulances and emergency departments. DeMaria et al4 have also expressed concern that such gatekeepers might reduce access to appropriate specialty care in emergency conditions.

The treatment of acute myocardial infarction (AMI) provides an ideal model for studying the quality of acute care for elderly HMO patients. Cardiovascular disease is the leading cause of disability and death in the elderly; 80% of all deaths caused by AMI occur in those aged 65 years or older.10 Strong evidence from large randomized clinical trials shows that early treatment with aspirin, thrombolytic agents, and β-blockers increases the rate of survival among elderly patients with AMI.11- 16 Because the benefits of treatment with thrombolytics decline rapidly within 6 hours after initial symptom onset,17 the time from symptom onset to hospital presentation is an important determinant of survival. Unfortunately, elderly patients with AMI are more likely to have atypical symptoms, delayed hospital presentation,18 and less frequent use of thrombolytic, β-blocker, and aspirin therapy.19

In this study, we reviewed the medical records of 2304 elderly patients admitted with AMI at 20 urban community hospitals in Minnesota to compare the quality of emergency care under HMO vs FFS insurance coverage. Specifically, we compared the use of emergency transportation, treatment delay (≥6 hours), time to electrocardiogram (ECG), use of drug treatments known to reduce morbidity and mortality in eligible patients with AMI (aspirin, thrombolytics, and β-blockers), and time from hospital arrival to thrombolytic administration (door-to-needle time). Unlike previous investigations,5 we attempted to identify specific mechanisms that might explain any observed insurance-related differences in quality of care, such as use of specialists.